Effect of Strip Tending Thinning on the Growth and Some Soil Nutrient Indexes of Larch Plantation in Eastern Liaoning Province

To study the effect of strip tending thinning on the growth of larch plantation and soil nutrient, larch plantation was taken as study object, different types of strip tending thinning were conducted with different species repair planted, growth factors and indexes of soil nutrient were determined and analyzed after 10 years. The results showed that DBH, individual volume and crown width of ST_I and ST_II were significantly higher than those of CK, DBH increased by 25.8% and 19.63%, individual volume increased by 53.01% and 31.68%, crown width increased by 49.29% and 45.99%, respectively; difference between growth factors of ST_I and ST_II was not significant, ST_I was better than ST_II on the whole. Effect of different repair planted species on growth factors of larch stands was not significant. The stem form of larch in the larch plantation was improved by strip tending thinning and repair planting. Strip thinning improved stand soil nutrient, especially the total phosphorus and available phosphorus content. In 0–10 cm soil, total phosphorus and available phosphorus content of ST_I and ST_II were 1.91 and 2.13 times, 2,22 and 1.62 times that of CK; in 10–20 cm soil, total phosphorus and available phosphorus content of ST_I and ST_II were 1.91 and 2.13 times, 1,79 and 1.44 times that of CK. Correlation analysis indicated that forest growth factor has correlation with soil nutrient, among which, growth factors have strong correlation with soil pH and phosphorus content. In a word, strip tending thinning may promote the growth of larch plantation and soil nutrient accumulation.